38 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 
the male genital] pore (VIII.-xI.) into somite xII., where it receives the ducts 
of the salivary glands, a bundle from either side of the body. 
The salivary glands themselves are very large in this species and are dis- 
tributed in the marginal part of the body through somites xI.—Xxvil., or, in 
exceptional cases, even a somite farther in one direction or the other. 
The short wsophagus (@., Figure 13) extends from the base of the proboscis 
through somite xI1I. to the beginning of the crop in somite XIV. 
The crop («glv., Figure 13) extends over the six somites XIV.—XIX., giving 
off in the middle of each a pair of conspicuous lateral diverticula. These are 
always evident whether the crop contains food or not, a condition very different 
from that which exists in G. stagnalis. The last pair of crop diverticula (those 
of somite XIx.) are very long but simple, as in G. stagnalis, without secondary 
lateral diverticula. They extend back over the entire stomach region, usually 
ending in somite XXIII. 
The stomach (ga., Figure 13), which is separated from the crop by a valve- 
like constriction, bears four pairs of lateral diverticula doubtless originally 
metameric in arrangement, but now arising within the limits of somites 
XX.—XXII. 
The intestine (in., Figure 13) leads from the stomach back to the anus, which 
is situated dorsally just behind somite xxvII., as in other species of Glossi- 
phonia. The intestine includes anteriorly two rather spacious chambers, the 
first of which bears a pair of small ear-like diverticula from its anterior lateral 
borders. Behind these chambers comes a simple tubular part terminating at 
the anus. 
To sum up, the particulars in which the digestive tract of G. fusca differs con- 
spicuously from that of G. stagnalis are (1) the shorter proboscis and larger 
cesophagus; (2) the larger salivary glands, distributed through a greater num- 
ber of somites; (3) the persistent character of the first five pairs of crop diver- 
ticula; (4) the distinctly chambered condition of the intestine, and the pair of 
diverticula borne by its first chamber. 
Nephropores are found on the sensory ring of each of the somites VIII.—XXTVv., 
with the possible exception of x1iI., where, as in stagnalis, the nephridia are 
much reduced, if not wholly wanting, —a fact accounted for by the strong 
development of the salivary glands and genital ducts in that region. The 
nephropore lies usually a little anterior to the middle of the ring on which it 
is found. 
e. Nervous SYSTEM. 
A ventral view of the brain is shown in Figure 18, a dorsal view of that part 
of it which lies above the pharyngeal sac is shown in Figure 16, the position 
of the ventral part being indicated by a dotted line ; the outline of the brain 
1 The animal shown in Figure 13 was a small one, and the salivary-gland cells 
are proportionally a little larger than they would be in the average, full-grown 
animal. 
